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Table 1 Vaccination, screening, cost parameters and transition probabilities

From: Cost-effectiveness of different human papillomavirus vaccines in Singapore

Parameters Base case Ranges Source
Vaccination    
Cohort size 25,000   [20]
Vaccine coverage 100%   Assumption
Age at vaccination 12   
Vaccine efficacy* - bivalent vaccine 87.2% 70%-95% [21, 22]
Vaccine efficacy* - quadrivalent vaccine 78.8% 70%-95% [23]
Duration of efficacy Lifetime 5 years to lifetime Assumption
Vaccine waning + booster None 5, 10, 20 years Assumption
Screening    
Screening age range 25-65   [4]
Screening interval every 3 years   [4]
Percentage screened per year 17% 10-20 Estimated
Cytology sensitivity to detect CIN1 0.58 none [18, 19]
Cytology sensitivity to detect CIN2/3 0.61 none [18, 19]
Compliance to CIN1 treatment 75% 50%-100% Assumption
Compliance to CIN2/3 treatment 75% 50%-100% Assumption
Cancer detection rate Low High  
Probability Of symptons CC1 0.075 0.185  
Probability Of symptons CC2 0.113 0.3  
Probability Of symptons CC3 0.3 0.75 [24, 25]
Probability Of symptons CC4 0.45 0.8  
Cost, SGD$ (2008)   (-20%/+50%) except vaccine cost (200-400)  
Vaccine cost per vaccinated woman, bivalent vaccine # 400   
Vaccine cost per vaccinated woman, quadrivalent vaccine# 400   Assumption
Cytology test^ 40   
Colposcopy and Biopsy^ 207   
CIN 1 treatment 1,105   
CIN 2/3 treatment 1,480   
Stage 1 Cancer treatment cost 9,388   Singapore public sector hospitals
Stage 2 Cancer treatment cost 9,765   
Stage 3 Cancer treatment cost 9,765   
Stage 4 Cancer treatment cost 11,047   
Genital warts 750   
Discounting    
Costs, Outcomes 3%, 3% (0%-5%) Assumption
Transition Probabilities    
Well to HPV 0.05 0-0.2  
HPV to clearance 0.4 0.29-0.55  
HPV to CIN1 0.05 0.014-0.14 [18, 19, 26]
CIN1 clearance 0.4 0.24-0.5  
CIN1 to CIN2/3 0.09 0.02-0.32  
CIN2/3 clearance 0.25 0.01-0.45  
CIN2/3 to persistent CIN2/3 0.11 0.03-0.20  
Persistent CIN2/3 to Cancer stage 1 0.05 0.001-0.15  
Cancer stage 1 to Cancer stage 2 0.22 0.11-0.4  
Cancer 1 to cancer cured 0.84 0.63-0.98  
Cancer stage 1 to Cancer stage 3 0.24 0.12-0.5  
Cancer 2 to cancer cured 0.66 0.49-0.83  
Cancer stage 3 to Cancer stage 4 0.24 0.12-0.8  
Cancer 3 to cancer cured 0.38 0.28-0.48 [21, 22, 2426]
Cancer 4 to cancer cured 0.11 0.08-0.14  
Detected CIN1 to well 0.9 0.8-1  
Detected CIN1 to Detected CIN2/3 0.09 0.02-0.32  
Detected CIN2/3 to Well 0.9 0.8-1  
Detected CIN2/3 to Detected PCIN2/3 0.11 0.03-0.20  
Detected PCIN2/3 to Cancer 1 0.05 0.001-0.15  
Mortality of cervical cancer 0.11   
Cervical Warts    
Effectiveness of vaccination against warts 0.90   [27, 28]
Cost of treatment 750   
Well to low risk HPV 0.050   
Low risk HPV to well 0.500   
Low risk HPV to CIN1 low risk 0.036   
Low risk HPV to warts 0.027   
Warts to well 0.875   
CIN1 low risk to well 0.500   
CIN1 low risk to detected CIN 1 low risk 0.099   
Detected CIN 1 low risk to well 0.950   
QALYs    
Disease free 1   
Genital warts 0.96 0.91-0.99 [10, 25, 29]
Detected CIN 0.89 0.84-0.94  
Cancer detected    
Stage I 0.65 0.49-0.81  
Stage II 0.56 0.42-0.70  
Stage III 0.56 0.42-0.70  
Stage IV 0.48 0.36-0.60  
Cancer cured 0.94   
  1. *Calculated, refer to Table 1b.
  2. #including costs of implementing, administration and support for vaccination programme
  3. ^including admininistrative cost & patient costs